PROJECT HIGHLIGHT
This study has compiled the largest microplastic dataset ever developed for Central California, identifying nearly 25,000 particles across rivers, beaches, coastal waters and marine wildlife, including blue whales. The research reveals that beaches act as major pollution sinks with concentrations approximately thirty times higher than river or ocean waters. The findings show that microplastic fibers, consistent with textile sources like denim, are especially common.
PROJECT SUMMARY
This project is quantifying microplastic movement across the Monterey Bay watershed and coastal ecosystem, filling a critical knowledge gap for central California between the San Francisco Bay and Southern California Bight regions. The research team has collected and analyzed more than 15,000 liters of river and ocean water and approximately 1,500 liters of beach sand from four major river systems (Salinas, Pajaro, San Lorenzo and Carmel), their associated beaches and offshore waters.
Laboratory analysis has revealed distinct patterns in how microplastics move through and accumulate in the environment. Beach sands contain the highest concentrations and appear to function as long-term sinks where plastics accumulate over time. Most particles in the larger size range are fibers, with blue fibers — consistent with denim microfibers from clothing — being especially common. White polystyrene foam fragments, likely from food packaging and recreational products, are abundant at certain beach locations.
Working with partners including Stanford University's Hopkins Marine Station and the National Oceanic and Atmospheric Administration, the team has also collected samples from forage fish, krill and blue whale fecal material to trace microplastics through marine food webs. Blue whale samples have revealed numerous synthetic fibers, demonstrating that microplastic exposure extends to the largest animals on Earth. Analysis of these biological samples is ongoing.
Matthew Savoca